/*
 * @(#)utf.c	1.4 06/10/26
 *
 * Copyright  1990-2008 Sun Microsystems, Inc. All Rights Reserved.  
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER  
 *   
 * This program is free software; you can redistribute it and/or  
 * modify it under the terms of the GNU General Public License version  
 * 2 only, as published by the Free Software Foundation.   
 *   
 * This program is distributed in the hope that it will be useful, but  
 * WITHOUT ANY WARRANTY; without even the implied warranty of  
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU  
 * General Public License version 2 for more details (a copy is  
 * included at /legal/license.txt).   
 *   
 * You should have received a copy of the GNU General Public License  
 * version 2 along with this work; if not, write to the Free Software  
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  
 * 02110-1301 USA   
 *   
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa  
 * Clara, CA 95054 or visit www.sun.com if you need additional  
 * information or have any questions. 
 *
 */


/* Misc functions for conversion of Unicode and UTF-8 and platform encoding */

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>

#include "jni.h"

#include "utf.h"

/*
 * Error handler
 */
void
utfError(char *file, int line, char *message)
{
    (void)fprintf(stderr, "UTF ERROR [\"%s\":%d]: %s\n", file, line, message);
    abort();
}

/*
 * Convert UTF-8 to UTF-16
 *    Returns length or -1 if output overflows.
 */
int JNICALL
utf8ToUtf16(struct UtfInst *ui, jbyte *utf8, int len, jchar *output, int outputMaxLen)
{
    int outputLen;
    int i;
    
    UTF_ASSERT(utf8);
    UTF_ASSERT(len>=0);
    UTF_ASSERT(output);
    UTF_ASSERT(outputMaxLen>0);
    
    i = 0;
    outputLen = 0;
    while ( i<len ) {
	unsigned code, x, y, z;
	
	if ( outputLen >= outputMaxLen ) {
	    return -1;
	}
	x = (unsigned char)utf8[i++];
	code = x;
	if ( (x & 0xE0)==0xE0 ) {
	    y = (unsigned char)utf8[i++];
	    z = (unsigned char)utf8[i++];
	    code = ((x & 0xF)<<12) + ((y & 0x3F)<<6) + (z & 0x3F);
	} else if ( (x & 0xC0)==0xC0 ) {
	    y = (unsigned char)utf8[i++];
	    code = ((x & 0x1F)<<6) + (y & 0x3F);
	}
	output[outputLen++] = code;
    }
    return outputLen;
}

/*
 * Convert UTF-16 to UTF-8 Modified
 *    Returns length or -1 if output overflows.
 */
int JNICALL
utf16ToUtf8m(struct UtfInst *ui, jchar *utf16, int len, jbyte *output, int outputMaxLen)
{
    int i;
    int outputLen;
    
    UTF_ASSERT(utf16);
    UTF_ASSERT(len>=0);
    UTF_ASSERT(output);
    UTF_ASSERT(outputMaxLen>0);
    
    outputLen = 0;
    for (i = 0; i < len; i++) {
        unsigned code;
	
	code = utf16[i];
	if ( code >= 0x0001 && code <= 0x007F ) {
	    output[outputLen++] = code;
	} else if ( code == 0 || ( code >= 0x0080 && code <= 0x07FF ) ) {
	    output[outputLen++] = ((code>>6) & 0x1F) | 0xC0;
	    output[outputLen++] = (code & 0x3F) | 0x80;
	} else if ( code >= 0x0800 && code <= 0xFFFF ) {
	    output[outputLen++] = ((code>>12) & 0x0F) | 0xE0;
	    output[outputLen++] = ((code>>6) & 0x3F) | 0x80;
	    output[outputLen++] = (code & 0x3F) | 0x80;
	}
	if ( outputLen > outputMaxLen ) {
	    return -1;
	}
    }
    output[outputLen] = 0;
    return outputLen;
}

int JNICALL
utf16ToUtf8s(struct UtfInst *ui, jchar *utf16, int len, jbyte *output, int outputMaxLen)
{
    return -1; /* FIXUP */
}

/* Determine length of this Standard UTF-8 in Modified UTF-8.
 *    Validation is done of the basic UTF encoding rules, returns
 *    length (no change) when errors are detected in the UTF encoding.
 *
 *    Note: Accepts Modified UTF-8 also, no verification on the
 *          correctness of Standard UTF-8 is done. e,g, 0xC080 input is ok.
 */
int JNICALL
utf8sToUtf8mLength(struct UtfInst *ui, jbyte *string, int length)
{
    int newLength;
    int i;
    
    newLength = 0;
    for ( i = 0 ; i < length ; i++ ) {
	unsigned byte;

	byte = (unsigned char)string[i];
	if ( (byte & 0x80) == 0 ) { /* 1byte encoding */
	    newLength++;
	    if ( byte == 0 ) {
	        newLength++; /* We gain one byte in length on NULL bytes */
	    }
	} else if ( (byte & 0xE0) == 0xC0 ) { /* 2byte encoding */
	    /* Check encoding of following bytes */
	    if ( (i+1) >= length || (string[i+1] & 0xC0) != 0x80 ) {
		break; /* Error condition */
	    }
	    i++; /* Skip next byte */
	    newLength += 2;
	} else if ( (byte & 0xF0) == 0xE0 ) { /* 3byte encoding */
	    /* Check encoding of following bytes */
	    if ( (i+2) >= length || (string[i+1] & 0xC0) != 0x80 
		                 || (string[i+2] & 0xC0) != 0x80 ) {
		break; /* Error condition */
	    }
	    i += 2; /* Skip next two bytes */
	    newLength += 3;
	} else if ( (byte & 0xF8) == 0xF0 ) { /* 4byte encoding */
	    /* Check encoding of following bytes */
	    if ( (i+3) >= length || (string[i+1] & 0xC0) != 0x80 
		                 || (string[i+2] & 0xC0) != 0x80
		                 || (string[i+3] & 0xC0) != 0x80 ) {
		break; /* Error condition */
	    }
	    i += 3; /* Skip next 3 bytes */
	    newLength += 6; /* 4byte encoding turns into 2 3byte ones */
	} else {
	    break; /* Error condition */
	}
    }
    if ( i != length ) {
	/* Error in finding new length, return old length so no conversion */
	/* FIXUP: ERROR_MESSAGE? */
	return length;
    }
    return newLength;
}

/* Convert Standard UTF-8 to Modified UTF-8.
 *    Assumes the UTF-8 encoding was validated by utf8mLength() above.
 *
 *    Note: Accepts Modified UTF-8 also, no verification on the
 *          correctness of Standard UTF-8 is done. e,g, 0xC080 input is ok.
 */
void JNICALL
utf8sToUtf8m(struct UtfInst *ui, jbyte *string, int length, jbyte *newString, int newLength)
{
    int i;
    int j;

    j = 0;
    for ( i = 0 ; i < length ; i++ ) {
	unsigned byte1;

	byte1 = (unsigned char)string[i];

	/* NULL bytes and bytes starting with 11110xxx are special */
	if ( (byte1 & 0x80) == 0 ) { /* 1byte encoding */
	    if ( byte1 == 0 ) {
		/* Bits out: 11000000 10000000 */
		newString[j++] = (jbyte)0xC0;
		newString[j++] = (jbyte)0x80;
	    } else {
		/* Single byte */
		newString[j++] = byte1;
	    }
	} else if ( (byte1 & 0xE0) == 0xC0 ) { /* 2byte encoding */
	    newString[j++] = byte1;
	    newString[j++] = string[++i];
	} else if ( (byte1 & 0xF0) == 0xE0 ) { /* 3byte encoding */
	    newString[j++] = byte1;
	    newString[j++] = string[++i];
	    newString[j++] = string[++i];
	} else if ( (byte1 & 0xF8) == 0xF0 ) { /* 4byte encoding */
	    /* Beginning of 4byte encoding, turn into 2 3byte encodings */
	    unsigned byte2, byte3, byte4, u21;

	    /* Bits in: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
	    byte2 = (unsigned char)string[++i];
	    byte3 = (unsigned char)string[++i];
	    byte4 = (unsigned char)string[++i];
	    /* Reconstruct full 21bit value */
	    u21  = (byte1 & 0x07) << 18;
	    u21 += (byte2 & 0x3F) << 12;
	    u21 += (byte3 & 0x3F) << 6;
	    u21 += (byte4 & 0x3F);
	    /* Bits out: 11101101 1010xxxx 10xxxxxx */
	    newString[j++] = (jbyte)0xED; 
	    newString[j++] = (jbyte)(0xA0 + (((u21 >> 16) - 1) & 0x0F));
	    newString[j++] = (jbyte)(0x80 + ((u21 >> 10) & 0x3F));
	    /* Bits out: 11101101 1011xxxx 10xxxxxx */
	    newString[j++] = (jbyte)0xED;
	    newString[j++] = (jbyte)(0xB0 + ((u21 >>  6) & 0x0F));
	    newString[j++] = byte4;
	}
    }
    UTF_ASSERT(i==length);
    UTF_ASSERT(j==newLength);
    newString[j] = (jbyte)0;
}

/* Given a Modified UTF-8 string, calculate the Standard UTF-8 length.
 *   Basic validation of the UTF encoding rules is done, and length is
 *   returned (no change) when errors are detected.
 *
 *   Note: No validation is made that this is indeed Modified UTF-8 coming in.
 *
 */
int JNICALL
utf8mToUtf8sLength(struct UtfInst *ui, jbyte *string, int length)
{
    int newLength;
    int i;

    newLength = 0;
    for ( i = 0 ; i < length ; i++ ) {
	unsigned byte1, byte2, byte3, byte4, byte5, byte6;
	
	byte1 = (unsigned char)string[i];
	if ( (byte1 & 0x80) == 0 ) { /* 1byte encoding */
	    newLength++;
	} else if ( (byte1 & 0xE0) == 0xC0 ) { /* 2byte encoding */
	    /* Check encoding of following bytes */
	    if ( (i+1) >= length || (string[i+1] & 0xC0) != 0x80 ) {
		break; /* Error condition */
	    }
	    byte2 = (unsigned char)string[++i];
	    if ( byte1 != 0xC0 || byte2 != 0x80 ) {
	        newLength += 2; /* Normal 2byte encoding, not 0xC080 */
	    } else {
	        newLength++;    /* We will turn 0xC080 into 0 */
	    }
	} else if ( (byte1 & 0xF0) == 0xE0 ) { /* 3byte encoding */
	    /* Check encoding of following bytes */
	    if ( (i+2) >= length || (string[i+1] & 0xC0) != 0x80
	                         || (string[i+2] & 0xC0) != 0x80 ) {
		break; /* Error condition */
	    }
	    byte2 = (unsigned char)string[++i];
	    byte3 = (unsigned char)string[++i];
	    newLength += 3;
	    /* Possible process a second 3byte encoding */
	    if ( (i+3) < length && byte1 == 0xED && (byte2 & 0xF0) == 0xA0 ) {
		/* See if this is a pair of 3byte encodings */
		byte4 = (unsigned char)string[i+1];
		byte5 = (unsigned char)string[i+2];
		byte6 = (unsigned char)string[i+3];
	        if ( byte4 == 0xED && (byte5 & 0xF0) == 0xB0 ) {
		    /* Check encoding of 3rd byte */
		    if ( (byte6 & 0xC0) != 0x80 ) {
			break; /* Error condition */
		    }
	            newLength++; /* New string will have 4byte encoding */
		    i += 3;       /* Skip next 3 bytes */
		}
	    }
	} else {
	    break; /* Error condition */
	}
    }
    if ( i != length ) {
	/* Error in UTF encoding */
	/*  FIXUP: ERROR_MESSAGE()? */
	return length;
    }
    return newLength;
}

/* Convert a Modified UTF-8 string into a Standard UTF-8 string
 *   It is assumed that this string has been validated in terms of the
 *   basic UTF encoding rules by utf8Length() above.
 *
 *   Note: No validation is made that this is indeed Modified UTF-8 coming in.
 *
 */
void JNICALL
utf8mToUtf8s(struct UtfInst *ui, jbyte *string, int length, jbyte *newString, int newLength)
{
    int i;
    int j;

    j = 0;
    for ( i = 0 ; i < length ; i++ ) {
	unsigned byte1, byte2, byte3, byte4, byte5, byte6;
	
	byte1 = (unsigned char)string[i];
	if ( (byte1 & 0x80) == 0 ) { /* 1byte encoding */
            /* Single byte */
	    newString[j++] = byte1;
	} else if ( (byte1 & 0xE0) == 0xC0 ) { /* 2byte encoding */
	    byte2 = (unsigned char)string[++i];
	    if ( byte1 != 0xC0 || byte2 != 0x80 ) {
	        newString[j++] = byte1;
	        newString[j++] = byte2;
	    } else {
	        newString[j++] = 0;
	    }
	} else if ( (byte1 & 0xF0) == 0xE0 ) { /* 3byte encoding */
	    byte2 = (unsigned char)string[++i];
	    byte3 = (unsigned char)string[++i];
	    if ( i+3 < length && byte1 == 0xED && (byte2 & 0xF0) == 0xA0 ) {
		/* See if this is a pair of 3byte encodings */
		byte4 = (unsigned char)string[i+1];
		byte5 = (unsigned char)string[i+2];
		byte6 = (unsigned char)string[i+3];
	        if ( byte4 == 0xED && (byte5 & 0xF0) == 0xB0 ) {
		    unsigned u21;
	           
		    /* Bits in: 11101101 1010xxxx 10xxxxxx */
		    /* Bits in: 11101101 1011xxxx 10xxxxxx */
		    i += 3; 
				    
		    /* Reconstruct 21 bit code */
		    u21  = ((byte2 & 0x0F) + 1) << 16;
		    u21 += (byte3 & 0x3F) << 10;
		    u21 += (byte5 & 0x0F) << 6;
		    u21 += (byte6 & 0x3F);

		    /* Bits out: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */

		    /* Convert to 4byte encoding */
		    newString[j++] = 0xF0 + ((u21 >> 18) & 0x07);
		    newString[j++] = 0x80 + ((u21 >> 12) & 0x3F);
		    newString[j++] = 0x80 + ((u21 >>  6) & 0x3F); 
		    newString[j++] = 0x80 + (u21 & 0x3F);
		    continue;
		}
	    }
	    /* Normal 3byte encoding */
	    newString[j++] = byte1;
	    newString[j++] = byte2;
	    newString[j++] = byte3;
	}
    }
    UTF_ASSERT(i==length);
    UTF_ASSERT(j==newLength);
    newString[j] = 0;
}

/* ================================================================= */

#if 1  /* Test program */

/*
 * Convert any byte array into a printable string.
 *    Returns length or -1 if output overflows.
 */
static int 
bytesToPrintable(struct UtfInst *ui, char *bytes, int len, char *output, int outputMaxLen)
{
    int outputLen;
    int i;
    
    UTF_ASSERT(bytes);
    UTF_ASSERT(len>=0);
    UTF_ASSERT(output);
    UTF_ASSERT(outputMaxLen>=0);
    
    outputLen = 0;
    for ( i=0; i<len ; i++ ) {
	unsigned byte;
	
	byte = bytes[i];
	if ( outputLen >= outputMaxLen ) {
	    return -1;
	}
	if ( byte <= 0x7f && isprint(byte) && !iscntrl(byte) ) {
	    output[outputLen++] = (char)byte;
	} else {
	    (void)sprintf(output+outputLen,"\\x%02x",byte);
	    outputLen += 4;
	}
    }
    output[outputLen] = 0;
    return outputLen;
}

static void
test(void)
{
    static char *strings[] = { 
	    	"characters", 
		"abcdefghijklmnopqrstuvwxyz", 
		"0123456789", 
		"!@#$%^&*()_+=-{}[]:;", 
		NULL };
    int i;
    struct UtfInst *ui;
    
    ui = utfInitialize(NULL);
    
    i = 0;
    while ( strings[i] != NULL ) {
	char *str;
	#define MAX 1024
	char buf0[MAX];
	char buf1[MAX];
	char buf2[MAX];
	unsigned short buf3[MAX];
	int len1;
	int len2;
	int len3;
    
	str = strings[i];
    
	(void)bytesToPrintable(ui, str, (int)strlen(str), buf0, 1024);
	
	len1 = utf8FromPlatform(ui, str, (int)strlen(str), (jbyte*)buf1, 1024);
	
	UTF_ASSERT(len1==(int)strlen(str));
	
	len3 = utf8ToUtf16(ui, (jbyte*)buf1, len1, (jchar*)buf3, 1024);
	
	UTF_ASSERT(len3==len1);
	
	len1 = utf16ToUtf8m(ui, (jchar*)buf3, len3, (jbyte*)buf1, 1024);
	
	UTF_ASSERT(len1==len3);
	UTF_ASSERT(strcmp(str, buf1) == 0);
	
	len2 = utf8ToPlatform(ui, (jbyte*)buf1, len1, buf2, 1024);
	
	UTF_ASSERT(len2==len1);
	UTF_ASSERT(strcmp(str, buf2) == 0);

	i++;
    }
    
    utfTerminate(ui, NULL);

}

int 
main(int argc, char **argv)
{
    test();
    return 0;
}

#endif

